379. If the first part is a noun, its stem is taken: as, #Ahēno-barbus#,
_Redbeard_, _Barbarossa_; usually with weakening of a stem vowel
(103-105): as, #aurifex#, _jeweller_ (#auro-#). On other changes of the
final vowel in the first member of compounds, see 174. Sometimes with
disappearance of a syllable (179); as, #*venēni-ficus#, #venē-ficus#,
_poisoner_ (#venēno-#); or of a vowel (111): as, #man-ceps#,
_contractor_ (#manu-#); particularly before a vowel (119): as,
#magn-animus#, _great-souled_ (#magno-#). Consonant stems are often
extended by #i# before a consonant: as, #mōri-gerus#, _complaisant_
(#mōr-#).
380. Stems in #-s-#, including those in #-er-#, #-or-# and #-ōr-# (236),
are sometimes compounded as above (379): as, #nemori-vagus#,
_woodranger_; #honōri-ficus#, _complimentary_; but usually they drop the
suffix and take #i#: as, #opi-fex#, _work-man_ (#oper-#);
#foedi-fragus#, _truce-breaker_ (#foeder-#); #volni-ficus#, _wounding_
(#volner-#); #mūni-ficus#, _generous_ (#mūner-#); #terri-ficus#,
_awe-inspiring_ (#terrōr-#); #horri-fer#, _dreadful_, #horri-sonus#,
_awful-sounding_ (#horrōr-#).
381. The second part, which often has weakening of the vowel (102), is
sometimes a bare root used as a stem (199), oftener a root with a
formative suffix; or a noun stem, sometimes with its stem ending
modified: as, #iū-dic-#, N. #iūdex#, _juror_ (√#dic-#, _declare_);
#causi-dic-o-#, N. #causidicus#, _pleader_ (209); #in-gen-io-#, N.
#ingenium#, _disposition_ (√#gen-#, _beget_, 219); #con-tāg-iōn-#, N.
#contāgiō#, _touching together_ (√#tag-#, _touch_, 227); #im-berb-i-#,
N. #imberbis#, _beardless_ (#barbā-#).